Large memory spike when spawning helper processes

Since upgrading to Claude Agent Python SDK 0.1.18, I am commonly seeing the following while running `client.query(query)` followed by `client.receive_response()`:

```
ERROR:claude_agent_sdk._internal.query:Fatal error in message reader: Command failed with exit code -9 (exit code: -9)
Error output: Check stderr output for details
```

After which the method fails with the error:

```
Command failed with exit code -9 (exit code: -9)
```

After this has occurred once, subsequent calls to `client.query` fail with the error:

```
Cannot write to terminated process (exit code: -9)
```

Exit code 9 is often caused by OOM Killer, meaning the process ran out of memory. These errors don't always happen immediately. Sometimes the SDK works for one or two calls, and then this happens.

This could potentially be caused by a memory leak in Claude Code.

Original issue: https://github.com/daytonaio/daytona/pull/3208